1. Field of the Invention
The present invention relates to an object, a method, or a manufacturing method. In addition, the present invention relates to a process, a machine, manufacture, or a composition of matter. In particular, one embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a storage device, a driving method thereof, or a manufacturing method thereof. In particular, one embodiment of the present invention relates to a secondary battery and a method for manufacturing the secondary battery. In particular, one embodiment of the present invention relates to an electrode of a lithium-ion secondary battery.
2. Description of the Related Art
Examples of a secondary battery capable of being charged and discharged include a nickel-metal hydride secondary battery and a lithium-ion secondary battery.
Such secondary batteries are often used as power sources in portable information terminals typified by mobile phones. In particular, lithium-ion secondary batteries have been actively developed because capacity thereof can be increased and size thereof can be reduced.
An electrode functioning as a positive electrode or a negative electrode of a lithium-ion secondary battery is formed with, for example, a lithium metal, a carbon-based material, or an alloy material. A lithium-ion secondary battery in which a group of whiskers including silicon is used for an electrode has been disclosed in Patent Document 1.